The main goal of this study is to functionalize SrO with carbon dots (C-dots) and to explore the composite as a catalyst for fatty acid methyl esters (FAME) production using Chlorella vulgaris as feedstock. C-dots are synthesized by sonicating polyethylene glycol followed by sonochemical modification of Sr(NO3)(2) (precursor for SrO) with C-dots. Sonication facilitates the adhesion of C-dots to the surface of Sr(NO3)(2). The resulting material is calcined in an inert environment to form a SrO-C-dot composite. The effect of functionalizing SrO with C-dots on the transesterification of the lipids in the alga with methanol is studied. The optimization of a one-stage process of conversion of the lipid fraction of microalga Chlorella vulgaris into FAME using direct transesterification under microwave irradiation is illustrated. A lipid conversion value of 45.5 wt % is achieved using the SrO-C-dot catalyst after 2.5 min of microwave (MW) irradiation. The catalyst displayed better activity than commercial SrO. Microwave irradiation accelerates the disruption of the microalgal cells and facilitates the release of lipid content into the reaction medium. The catalyst is characterized by a variety of physicochemical techniques. The FAME product obtained from the alga is quantified using H-1 NMR spectroscopy. The new catalyst, namely, SrO-C-dot nanoparticles (NPs), yielded 97 wt % FAME from Chlorella vulgaris in 2.5 min of MW irradiation.